\
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.TH "Pnminvert User Manual" 1 "08 August 1989" "netpbm documentation"

.SH NAME

pnminvert - invert a PNM image

.UN synopsis
.SH SYNOPSIS

\fBpnminvert\fP

[\fIpnmfile\fP]

.UN description
.SH DESCRIPTION
.PP
This program is part of
.BR "Netpbm" (1)\c
\&.
.PP
\fBpnminvert\fP reads a PNM image as input, inverts it black for
white, and produces a PNM image as output.
.PP
If the image is grayscale, \fBpnminvert\fP replaces a pixel with
one of complementary brightness, i.e. if the original pixel has gamma-adjusted
gray value G, the output pixel has gray value maxval - G.
.PP
If the image is color, \fBpnminvert\fP inverts each individual RGB
component the same as for a grayscale image.

.UN options
.SH OPTIONS
.PP
There are no command line options defined specifically
for \fBpnminvert\fP, but it recognizes the options common to all
programs based on libnetpbm (See 
.UR index.html#commonoptions
 Common Options
.UE
\&.)

.UN seealso
.SH SEE ALSO
.BR "pnm" (1)\c
\&

.UN author
.SH AUTHOR

Copyright (C) 1989 by Jef Poskanzer.
.SH DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source.  The master documentation is at
.IP
.B http://netpbm.sourceforge.net/doc/pnminvert.html
.PP